1. Field of the Invention
The present invention relates generally to improvements in networked multi-entity systems for scanning bar codes, and particularly to advantageous aspects of a system and methods for collaborative bar code error detection and correction in a networked multi-entity environment.
2. Description of the Prior Art
Bar coding systems, such as the Uniform Product Code (UPC) system, are commonly used to identify items, such as products for sale in a retail store. In such systems, bar codes consisting of a series of bars and spaces of varying widths are printed onto labels that are affixed to the products for sale, or are printed directly onto the product packaging. Scanners at the checkout terminals are then used to read the bar codes. This approach allows more information to be entered in less time, as scanning requires significantly less time than manually entering pricing and product identification information. Further, the use of bar codes eliminates errors arising from keyboarding errors by checkout personnel.
Bar-coded labels are not always printed perfectly. Imperfections caused by the printing process frequently render the printed bar code unreadable to the bar code scanning equipment. However, systems have been developed that are able to detect and correct certain classes of label defects. These include, for example, U.S. Pat. No. 5,767,498, assigned to the assignee of the present application and incorporated herein by reference in its entirety. Such systems have operated as non-networked, individual entities. Thus, a scanner incorporating one of these error detection and correction systems is only able to learn and act upon the data seen by that scanner, without being able to take advantage of data from other scanners.
One aspect of the invention provides a system for collaborative bar code error detection and correction, comprising a network of individual scanning entities for scanning bar-coded labels. Each individual scanning entity includes a scanning system having a decoder for decoding scanned bar code information and a printhead defect identifier for identifying printhead defects from scanned bar code information that cannot be decoded and for constructing printhead defect models for use in correcting future bar code scans. A log is provided at each individual scanning entity for storing locally constructed printhead defect models and printhead defect models that have been constructed at other scanning entities in the network. Each individual scanning entity has an error corrector for correcting erroneous scanned bar code information using the locally stored printhead defect models. Further, each scanning entity includes a network connection for broadcasting locally constructed printhead defect models to the network and for receiving broadcasts of printhead defect models constructed at other scanning entities in the network.
Additional features and advantages of the present invention will become apparent by reference to the following detailed description and accompanying drawings.